Switch



Jan. 12, 1932. M, B BLOOM E1- A| 1,840,691

SWITCH Filed June 18, 1930.

VIII

@hoi/nuja Patented Jan. 12, 1932 UNITED sTATEs PATENT OFFICE f MORRIS B.BLOOM AND JOSETH L. BERNSTEIN, F HARTFORD, CONNECTICUT, ASSIGNORS OFONE-THIRD T0 HARRY BLOOM, OF HARTFORD, CONNECTICUT SWITCH Applicationled June 18,

The invention relates to an improved device for completing an alarmcircuit when a liquid in a tank reaches a predetermined level, theprincipal use of the invention being to indicate when the fuel in thesupply tank of a liquid fuel burner (domestic or industrial), is low andrequires replenishing, the construction being such that it may beeffectively used w whether the tank bel below or above the ground orfloor level.

When the switch is installed, it is controlled by a float in the tank,float and switch being connected by a chain or other flexible memberpassing through a pipe. This pipe supports the switch-containing casingand necessarily,

communicates with this casing and the tank, and it is one important aimof the invention to provide a novel constructionpreventing gas or fumesfrom the tank, from escaping to the building or furnace room by way ofsaid pipe and casing, at the same time providing for enclosing allswitch parts and electrical connections for safety and protectivepurposes.

A further aim of the invention is to provide a structure of extremelysimple and inexpensive nature, one which cannot easily getout of orderand one which will be long-lived and continuously eliicient.

With the foregoing in view, the invention resides in the novel subjectmatter hereinafter described and claimed, description being accomplishedby reference to the accompanying drawings. l

Fig. 1 is a vertical sectional view partly in elevation showing theinvention operativelyconnected with a tank, aremovable side wall of theswitch containing casing, being detached in this view.

Fig. 2 is a horizontal sectional view on line 2-2 of Fig. 1. n Fig. 3 isa vertical sectional view on line 3-3 of Fig. 1.

Fig. 4 is a perspective view of the switch lever and associatedelements.

The numeral 5 on the drawings denotes a liquid-containing tank withwhich a pipe 6 is rigidly connected, said pipe extending up- A wardlyfrom said tank and being threaded 1930. serial No. `4.611,091.

into a neck 7 on the bottom 8 of a casing 9, which casing contains aswitch and electrlcal connections therefor. A float 10 is provided inthe tank 5 for closingthe switch when the liquid in said tank lowers toa predetermined level, said iioat being connected with the lower end ofa chain 11 which passes through the pipe 6, the upper end of the chainbeing connected with the switch as hereinafterV described. This chain ispreferably of the con-A ventional bead-like form, commonly used for pullchains on electrical xtures, and by providing a chain of this type,there is no liability of it becoming tangled or caught upon any parts.

The casing 9 is preferably of two-part construction and formed fromalvanized, castiron or the like. One part o this casing constitutes themajority of the' latter and embodies the bottom 8, the top 12, twovertical side walls 13 and 14, a back wall 15, and a horizontalpartition 16. The casing portions 8, 12, 13, 14 and 16 are of uniformwidth and are all integrally joined to each other. The other part of thetwo-part casing is constituted by a removable front side wall'17 whichis secured in place by screws or the like 18, a packing sheet 19 beingclamped between said wall 17 and the front edges of the casing parts 8,12, 13, 14 and 16. The partition 16 divides the casing 9 into a lowerswitch chamber S and an upper conductorconnecting chamber C, chamber Sbeing provided with the neck 7 and chamber 15 being provided with asimilar neck 19 for connecting a conductor conduit 20 thereto. Thisconduit may of course be either a pipe or the conventional flexiblearmor. The conductors passing through the pipe are denoted at 21. TwoopeningIsJ 22 are formed through the partition 16. assing through theseopenings are two binding posts 23 provided not only with means 24insulating them from the partition 16, but with packing means 25preventing any gases or fumes from ascending to the chamber C from thechamber S, so that these fumes cannot travel on through the conduit 20and escape into any portion of the building in which the invention `isused. The upper ends of the binding posts 23 are provided with nuts 26in the chamber- C for the purpose of clamping the conductors 2l to saidbinding posts. T he lower ends of these binding posts are provided withnuts 27 in the chamber S, said nuts connecting said posts with twoilexible conductors 2S. These conductors 2S are provided with electrodes29 in a tube 30 containing a quantity oi' mercury Si, and when saidelectrodes are bridged by the mercury, the circuit for the alarm iscompleted.

A lever 32 is provided to carry the tube 30. This lever is fulcrumedbetween its ends at 33 and is provided with a spring clip 34 which holdsthe tube 30. One end of lever 32 is disposed over the neck 7 and isconnected with the upper end of the chain l1. The other end of lever 32is provided with a weight 35 held in place by a screw or the like 36.This weightnormally overbalances the weight of the chain ll. and holdsthe lever 32 in the position shown in F ig. l, said weight then restingupon the bottom 8. In this position of the lever, the mercury 3l is atthe end ot' the tube 8() remote from the electrodes 29, and the chain llis slack within the tank 5, until the liquid level lowers beyond apredetermined extent. Vhen such lowering takes place, however, the float10 descends, pulls upon the chain ll and overcomes the action of theweight 35, the result being that the lever .32 is tilted to cause themercury 3l to descend by gravity against the electrodes 29. Thus, uponlowering of the liquid level beyond a predetermined extent, the alarmcircuit is completed.

It will be seen from the foregoing that the invention is simple andinexpensive, may be readily manufactured and sold at small cost, will beellicient and long-lived, will afford eliective protection for allelectrical connections and switch parts, and will prevent escape ot anygases or fumes. On account ol these advantages, the details disclosedare preferably followed. However, within the scope of the invention asclaimed, variations may of course be made.

We claim:

In a gas seal and level indicator switch for a fuel tank, a casing abovesaid fuel tank comprising a vertical back wall, top and bottom walls,vertical side walls and a horizontal partition wall; said top, bottom,side and partition walls being of uniform width and being unitarily andgas-tightly connected with said back wall; said side walls beingunitarily and gas-tightly connected also with said top, bottom andpartition walls; and a one-piece removably secured front wall ly inggas-tightly against the free edges of said top, bottom, Side andpartition walls, removal of said front wall serving to give access tothe interior of the casing both above and below said partition wall;said bottom having a pipe-connecting opening and one of said wallshaving a conductor entrance opening above said partition wall, avertical pipe connected gas-tightly with and rising from the fuel tank,the upper end of said pipe being gas-tightly secured in said pipe-c011-necting opening, binding posts passing gastightly through and insulatedfrom said partition wall, the upper ends of said binding posts beingaccessible for conductor connection when said front wall is removed, aswitch mounted in said casing below said partition wall and conductivelyconnected with said binding posts, a switch-operating member looselyreceived in said pipe and connected at its upper end with said switch,and a float in the fuel tank connected with the lower end of saidswitch-operating member.

In testimony whereof we affix our signa-

